1. Field of the Invention
This invention relates to a method for surface treating a photographic support member having a polyolefin surface and more particularly, it is concerned with a method whereby the adhesiveness of a photographic emulsion layer and support is improved by application of a flame containing excess oxygen to the surface of said support.
2. Description of the Prior Art
A previous attempt to give adhesion of printing inks or various coating materials to formed articles of polyolefins consists in subjecting the polyolefin surface to a flame treatment, that is, by exposing to a high temperature flame in a short time (U.S. Pat. No. 2,632,921 and U.S. Pat. No. 2,648,097). The composition of a combustion gas in a flame treatment is described in detail in British Pat. No. 1,010,649.
When the above-described flame treatment is applied to a photographic support having a surface of polyolefin, that is, using the gaseous composition described in British Pat. No. 1,010,649, a sufficient adhesive strength is not obtained between the photographic emulsion layer on the support surface-treated by the flame. Also, a disadvantage in that fog of the light-sensitive emulsion even under non-exposed conditions occurs. Practical use of the flame treatment is thus made difficult.
We, the inventors, have made efforts, in particular, studies on the composition of the combustion gas so as to overcome the foregoing disadvantages in flame treatment and have reached the invention.